class_docstr: A RetryError encapsulates the last Attempt instance right before giving up.
code: def __str__(self):
      return "RetryError[{0}]".format(self.last_attempt)
  
imports: import random
  import six
  import sys
  import time
  import traceback
label_desc: Use image node_id 2 for calling the RetryError obj's underlying member method code with example usage: obj.__str__() and returns: str